Originally Posted by AyanEva
I was thinking that they're fully charged or at maximum operation/capacity/whatever. They're working at 100% efficiency.
Yupp. The warp core is a fancy fusion reactor and needs an electromagnetic forcefield to keep the fusion reaction away from the housing of the chamber. When this electro magnetic force field gets instable we have a warp core breach (the antimatter gets in contact with the reactor housing, reacts with its matter and consumes the whole ship).
So, Scotty's words could be taken as meaning the electromagnetic containment field of the dilithium chambers are stable, running and tested for maximum capacity - dilithium chambers on full.
But anyway, I must agree with FanWriter, it sounded verry odd.
Take a core fusion reactor as reference. It also needs electro magnetic fields to operate and to keep the hot plasma away from the reactors housing. Otherwise the plasma cools down rapidly and the reaction stops.